docs: def write(self, s):
          """First preprocess the string `s` to prettify it (assuming it is argparse
          help output).  Then write the result to the outstream associated with the
          class."""
          pretty_str = s
          for pair in self.help_string_replacement_pairs:
              pretty_str = pretty_str.replace(pair[0], pair[1])
          # Define ^^s as the bell control char for now, so fill will treat it right.
          pretty_str = pretty_str.replace("^^s", "\a")
  
          def do_fill(match_obj):
              """Fill function for regexp to apply to ^^f matches."""
              st = pretty_str[match_obj.start()+3:match_obj.end()-3] # get substring
              st = re.sub("\n\s*\n", "^^p", st).split("^^p") # multi-new to para
              st = [" ".join(s.split()) for s in st] # multi-whites to single
              wrapper = textwrap.TextWrapper( # indent formatted paras
                  initial_indent=" "*self.init_indent,
                  subsequent_indent=" "*self.subs_indent,
                  width=self.line_width)
              return "\n\n".join([wrapper.fill(s) for s in st]) # wrap each para
  
          # Do the fill on all the fill sections.
          pretty_str = re.sub(r"\^\^f.*?\^\^f", do_fill, pretty_str, flags=re.DOTALL)
          pretty_str = pretty_str.replace("\a", " ") # bell character back to space
          pretty_str = pretty_str.replace("^^n", "\n") # replace ^^n with newline
          self.outstream.write(pretty_str)
          self.outstream.flush()